Researchers at the medical center have discovered a new
application for a specialized procedure called Mohs micrographic
surgery that could increase the cure rate of an invasive fungal
disease.

The
disease, known as cutaneous mucormycosis, primarily affects
patients who are immunocompromised, particularly those who have
diabetes, leukemia or who have undergone an organ
transplant.

A
paper recently published in Dermatologic Surgery described
the novel application of Mohs surgery, considered the gold-standard
for treating non-melanoma skin cancers. Mohs requires surgeons to
painstakingly remove diseased tissue layer by layer, studying the
pathology of each layer as they go in an effort to leave as much
healthy tissue as possible intact.

The
discovery could be significant for transplant patients susceptible
to infection.

"Mucormycosis in immunocompromised patients is extremely
serious and can be fatal," said Hayes Gladstone, MD, one of the
study’s authors and director of Moh’s micrographic
surgery and cutaneous laser surgery at the medical
center.

Observed under a microscope, mucormycosis is a fungus with
tree-like branches that jut out at 90-degree angles. These
"branches" normally invade blood vessels, blocking off the blood
supply, killing tissue and causing necrosis. The fungus can grow
very quickly in a human being.

Gladstone treated a man who had undergone an organ transplant
three years prior. The patient had developed a growth on one of his
elbows. "He had pneumonia and was pharmacologically suppressed, so
it kept growing," said Gladstone, assistant professor of
dermatology.

"A
biopsy was performed and it was mucormycosis. In many cases in the
past, amputation may have been a reasonable option. But we could
offer him this procedure and we were able to clear the fungus.
After a year, there’s no recurrence."

While this procedure is most commonly used for treating skin
cancers, Gladstone believes it’s a suitable technique for
removing other types of tumors. Surgeons bevel the blade of a
scalpel at a 45-degree angle or more, which is not normal for
standard excisional surgery. This way, a surgeon gets more of a
saucer-shaped specimen to see the "entire critical
margin."

"We
also draw on a special piece of paper the exact shape of the
specimen, then we’ll look at it under the microscope," said
Gladstone. "We can see exactly where the fungus is and then map it
exactly on a precise drawing. That technique allows us to cut out
the portion where there’s fungus as opposed to cutting out a
wide excision. We can save skin rather than making a huge
defect."

According to Gladstone, the technique in combination with the
traditional use of the antifungal drug amphotericin potentially can
spare some patients from more radical surgery such as amputation
and decrease morbidity for the patient. "Ultimately, that leads to
better patient care," he said.

While this is the first reported case of using Mohs
micrographic surgery to treat mucormycosis, Gladstone and his
colleagues reported that the techniques needs further study to
create clinical guidelines.

Stanford researchers who contributed to the study include
Landon Clark and R. Sonia Batra, MD.